24
25
• Press TIMER and the display will show the countdown prior to the measurement or, alternatively, wait
for 2 minutes and 30 seconds and press READ. When the timer ends the meter will perform the reading.
• The instrument displays the results in mg/L of total chlorine.
Note: free and total chlorine have to be measured separately with fresh unreacted samples following the
related procedure if both values are requested.
INTERFERENCES
Interference may be caused by: Bromine, Iodine, Ozone, Oxidized forms of Chromium and Manganese.
In case of water with hardness greater than 500 mg/L CaCO
3
, shake the sample for approximately 2
minutes after adding the powder reagent.
In case of water with alkalinity greater than 250 mg/L CaCO
3
or acidity greater than 150 mg/L CaCO
3
,
the color of the sample may develop only partially, or may rapidly fade. To resolve this, neutralize the
sample with diluted HCl or NaOH.
Total Chlorine
Total Chlorine
• Press ZERO key. The meter will show “-0.0-” when the meter is zeroed and ready for measurement.
• Remove the cuvette.
Powder reagents procedure
• Add 1 packet of HI 93711-0 DPD reagent. Replace the cap and
shake gently for 20 seconds (or 2 minutes for seawater analysis).
• Reinsert the cuvette into the instrument.
• Press TIMER and the display will show the countdown prior to the
measurement or, alternatively, wait for 2 minutes and 30 seconds and
press READ. When the timer ends the meter will perform the reading.
The instrument displays the results in mg/L of total chlorine.
Liquid reagents procedure
• To an empty cuvette add 3 drops of HI 93701A-T
DPD1 indicator, 3 drops of HI 93701B-T DPD1 buffer and
1 drop of HI 93701C DPD3 solution. Swirl gently to mix
and immediately add 10 mL of unreacted sample.
Replace the cap and shake gently again.
• Reinsert the cuvette into the instrument.
x 3
x 3
x 1
